Method and apparatus for carding fiber by fluid means



Jan. 1966 P. M. STRANG ETAL 3,228,067

METHOD AND APPARATUS FOR CAHDING FIBER BY FLUID MEANS Filed Dec. 20,1962 2 Sheets-Sheet 1 "f-a'a'auaa 1 jizz ezziara Peder! 557w ,Zra/lawz6.5 JZZZIfiZ/klf 7 0m Jan. 11, 1966 P. M. STRANG ETAL 3,228,067

METHOD AND APPARATUS FOR GARDING FIBER BY FLUID MEANS Filed Dec. 20,1962 2 Sheets-Sheet 2 y y LHVNT OF y 2 2 BOUNDARY 2 ff E5l1 I z F E 2 192 14L L l FIBER X J HELD HERE F I G. 3

IN VENTORS PETER fry/9N6 BRANDON G. RlGHTMlRE JOHNSON V/V/H/V BY WMQ-CQM ATTORNEYS United States Patent 3,228,067 METHOD AND APPARATUS FURCARDHNG FIBER BY FLUID MEANS Peter M. Strung, 31 Laurel Drive, Needham,Mass; Brandon G. Rightmire, 11 Kenmore Road, Belmont, Mass; and JohnsonE. Vivian, 35 Hutchinson Road, Arlington, Mass.

Filed Dec. 20, 1962, Ser. No. 246,128 11 Claims. ((11. 19-66) Thisinvention pertains to the preparation of fibrous material for use, forinstance, in the manufacture of fabrics, including those generallyclassified as textiles, as well as those recognized as papers, andrelates more especially to a method of and apparatus for so treatingfibers, for example (but without limitation), cellulosic fibers, eithernatural or synthetic, as to separate and straighten the fibers byhydraulic forces while arranging them in predominantly parallelrelation, and wherein, during the treatment, the fibers are suspended ina liquid medium, usually water.

It is, of course, customary in the textile industry to subject fibrousmaterial to a mechanical carding operation, wherein the fibers aresubjected to the action of relatively moving toothed elements, with theprimary purpose of separating and straightening individual fibers and,as more or less incidental thereto, arranging them in generally parallelrelation. In some instances, it has been proposed to supplement theaction of such toothed elements by appropriately created and directedair currents.

It has also been proposed to spin textile fibers by the use of aircurrents and, as an incident to such method, to subject the fibers toair jets or currents so directed as to separate the fibers and allegedlyto arrange them in parallel relation immediately before twisting them toform a yarn, but so far as is known, it has not heretofore been proposedto separate and straighten individual fibers and dispose them ingenerally parallel relation so as to form a layer of substantiallyuniform thickness, solely by the action of flowing fluid, in particulara liquid of a viscosity approximating that of water or air.

In accordance with the present invention, use is made, it is believedfor the first time, of certain well-known properties of flowing liquidto separate and straighten fibers and to lay them down to form a uniformlayer, if desired, of but a few fibers in thickness and of substantialwidth, all as a continuous operation thereby providing carded fibers incondition for spinning, and which, if desired, may be delivered directlyto spinning apparatus, either of the usual mechanical type or of thehydraulic type. The fibrous layer or film, produced as above suggested,if not of suflicient thickness itself for the intended purpose, asformed, may be assembled with other similar layers to form a multiplymaterial whose constituent itibers are substantially straight andparallel and which are held in assembled relation cohesively, adhesivelyor otherwise, for the production of certain kinds of unwoven fabrics ofthe type wherein fibers or strands, according to prior methods, havebeen disposed in parallel relation by mechanical means.

Generally stated, the present method involves the steps of suspendingthe selected fibrous material in a body of water, which may contain adispersing or deflocculating chemical; agitating the liquid so that thefibers are loosened and, to a substantial degree, separated; thendelivering the liquid with the suspended fibers into a sluiceway orchannel along which it flows into the field of action of means, forexample, one or more slowly moving toothed rollers, operative to retardmasses of unseparated fiber relatively to the liquid so as to permitsuch masses to be further disintegrated by the flowing liquid. Theliquid, with the suspended, separated fibers then enters the receivingend of a converging channel between the convex peripheral surface of arotating imperforate cylindrical drum which defines the inner boundaryof a flowing liquid stream, and the concavely curved surface (eccentricwith reference to said convex surface) of an imperforate fixed partwhich defines the outer boundary of said flowing stream of liquid,substantially all of the liquid, with the now generally parallel fiberstherein, being discharged at the narrow or delivery end of saidconverging channel (which is devoid of exit ports between its entranceand delivery ends), for example, onto the upper run of an endlessconveyor, of a type which permits the water to pass down through it,leaving the fibers upon the upper surface of the conveyor from whichthey may be removed in any desired manner as a coherent web, ordelivered directly to spinning apparatus of any desired type.

During the flow of fluid through the converging channel, viscosity andvarying velocity gradients of the flowing liquid result in separatingand drawing the fibers out relatively to one another so that they areindividually straightened and have a tendency to become parallel.

An object of the invention, as above noted, is to provide a method ofcarding fibers hydraulically in accordance with a procedure which may becarried out by very simple and relatively inexpensive means, as comparedwith usual mechanical carding apparatus, and whereby it becomespossible, at a high rate of speed, to straighten individual fibers anddispose the fibers in generally parallel relation to form if desired alayer or film of any reasonable width. This novel method is applicable,not only to the carding of fibers of textile staple length, but also tomuch shorter fibers, for example those customarily employed in themanufacture of papers. A further object is to provide novel apparatusfor use in the practice of the method.

In the following more detailed description reference will be made to theaccompanying drawings wherein:

FIG. 1 is a fragmentary diagrammatic, vertical section, with partsbroken away and others omitted-at right angles to the axis of therotating drum or cylinder which defines one wall of the convergingchannel-showing one embodiment of apparatus useful in the performance ofthe novel method;

FIG. 2 is a diagrammatic view wherein the essential elements of theapparatus of FIG. 1 are again shown for convenience in describinggraphically the varying veloc ities of the liquid as it flows throughthe convergent channel; and

FIG. 3 is a diagrammatic view, to very large scale, illustrative of theforces which act upon a single fiber as it is advanced by the current offlowing liquid.

Referring to the drawings, the numeral 10 (FIG. 1) diagrammaticallyindicates a receptacle of any desired kind and size, having arrangedtherein a stirring element of any appropriate type indicated at 11,whereby the contents of the receptacle may be agitated. An adjustablegate G governs the size of an orifice 0 through which liquid may flowinto a conduit 12 providing a sluiceway terminating at 13, where thereis arranged a feed roll 14, desirably a cylinder covered with helicalrows of pins or teeth, similar for example, to card clothing, mounted ona rotating shaft 15 which may be turned at slow speed, or merelyretarded by a brake or the like and which is operative to obstruct thefree movement of small masses of fibers which have not been broken up inthe tank 10, so that, as the liquid flows past the toothed roll, the nowturbulent flowing liquid acts to disintegrate the retarded lumps ormasses of fiber. The flowing stream of liquid, with the loosened fibersuspended therein, now enters the receiving end 16 of a convergentchannel 17 whose outer Wall is the concavely curved, smooth, imperforatesurface 18a of a fixed part 18, said smooth surface defining the outerboundary of the flowing fluid stream, the inner wall of the channelbeing constituted by a portion of the peripheral surface 19 of a smooth,imperforate drum or cylinder 20 mounted on a rotating shaft 21a, saidsmooth, peripheral surface of the drum defining the inner boundary ofthe flowing liquid stream. Just beyond the delivery end of the channel17, a blade-like member 21 is arranged with its edge very close to theperiphery of the cylinder so as to remove therefrom any fibrous materialwhich may tend to cling to the cylinder. As here illusrated, by way ofexample, the liquid, with its entrained, predominantly parallel fibers,which escapes from the narrow end of the channel 17, is discharged ontothe upper surface of an endless conveyor 22 which may, for instance, besimilar to a so-called Fourdrinier wire, such as is used in papermakingmachines, or it may be of textile material of a weave structure suchthat it is porous so as to permit the ready downward movement of thewater, leaving the parallel fibers as a thin layer or film F on theupper surface of the conveyor-it being understood that the upper run ofthe conveyor will be moved uninterruptedly in the direction of the arrowAthe conveyor being entrained around parallel drums R and R one of whichis driven. Desirably, a receptacle 23 is arranged below the conveyor forcollecting the water which is discharged from the conveyor and from thisreceptacle a suitable conduit 24 leads to any suitable point ofdischarge. As illustrated, a rotary roll or cylinder R is arrangedclosely adjacent to the downwardly moving portion of the conveyor 22 asthe latter passes around the drum R the roll R being so close to thedownwardly moving portion of the conveyor as to press the fibrous filmand compact it, and to direct it downwardly as it leaves the conveyor sothat it may conveniently be received in any appropriate receptacle ordelivered directly by appropriate conveying apparatus (not shown) tospinning mechanism.

Study of FIGS. 2 and 3 above, shows that the forces developed byapparatus such as herein described, whereby fibers may be straightenedand arranged in parallel relation, greatly exceed those forces developedby the usual flat card wherein the fibers are exposed to air only. Thus,by the use of apparatus far simpler and less expensive than the usualfiat cards and requiring a far lesser expenditure of power, the presentinvention provides a greatly improved method for preparing fibrousmaterial for textile or papermaking use.

Merely by way of example, but without limitation, the drum or cylinder20 may be of an external diameter of 9 inches; the diameter of theconcave surface 18a of the fixed part 18 is desirably between %10 /2inches and of circular curvature; the receiving or larger end of thechannel 17 may be of the order of one inch in radial width; and thenarrower or delivery end of the channel 17 of a radial width of A inch.The edge of blade 21 may be spaced from the cylinder 2% a distance ofthe order of ,6, of an inch, and the cylinder may rotate at 240 rpm.

It is desirable, when treating certain types of fiber, for instance,cotton fiber, as an initial step in the process, to suspend the fibersin liquid containing a chemical of the type known in the papermakingindustry as a deflocculant.

It will be understood that the drum or cylinder 20 will be housed Withina suitable casing (not here shown); that the opposite ends of thechannel 17 will be closed, leak-tight; and that suitable means (notshown) will be provided for rotating the cylinder 20 and (if desired)the toothed feed roll 14 at proper relative velocities, as, for example,by the use of an electric motor and conventional speed-reducing andtransmitting means. The drawings are only designed to show the essentialelements for carrying the method into effect and the relativearrangement of said elements, with exemplary dimensions of these partssuggested in the specification.

Using apparatus such as herein disclosed, wherein the cylinder 20 is 9inches in diameter and 40 inches in length; the inlet end of the channelis one inch in width and the outlet end is 4 inch in width, and with thecylinder 20 turning at 240 r.p.m., the output of parallelized andstraightened fiber (starting with a slurry consisting of 1% fiber, byweight, and the remainder water), would be approximately 47 pounds perhour of treated fiber, as compared with the present day production of a40 inch, top-fiat mechanical card of about 10 pounds per hour on theaverage. Apparatus of the present type, being far cheaper than theconventional card and requiring no such complicated and accuratesettings as does the conventional card, might, as a practical matter, bearranged in tandem or series if, in dealing with any particular fibrousmaterial, the straightening and parallelizing of fibers resultant frompassage through a single apparatus of this type, should not provesufficient for the intended purpose. It is contemplated that thisapparatus may be employed for treating short fibers of customarypaperstock length, but, in particular, longer fibers such as areemployed in making certain heavy papers such as for insulating purposes,as well as for the manufacture of unwoven textile fabric.

By the use of apparatus such as above described, it is possible to form,on the upper surface of the conveyor 22, a film or layer of fibrousmaterial wherein the individual fibers are approximately straight andparallel to each other. The layer or film, thus formed, is usuallysufiiciently coherent to permit it to be separated from the conveyorwithout destroying it. For example: the layer which is forming upon theconveyor may be removed therefrom by means similar to that employed forremoving the fleece from the dolfer of a conventional mechanical card,and condensed to form a sliver.

For an understanding of the principle of operation,

Ia. General description The apparatus consists essentially of a rotatingcylinder, half of the circumference of which is covered by a stationary,curved plate forming a convergent channel between itself and the movingcylindrical surface, as shown in FIG. 1. This channel is kept filledwith water by means of a suitable inclined trough, and a controlled feedof fibers is maintained by means of a slowly rotating, toothed drum setat the entrance to the channel. As the fibers are carried through thechannel the forces exerted on them by the water tend to parallelize andstraighten them.

Referring to FIG. 2 of the drawings, the apparatus diagrammaticallyshown is such that the fluid flow will be turbulent, rather thanlaminar. Thus, at any point in the channel 17 the velocity will befluctuating about a 'mean value. In the following description of theflow, reference will be made only to the mean velocity.

Ila. Characteristics of the flow Since no liquid enters the channelexcept at the entrance Section I of FIG. 2 and none leaves except at theexit Section III, the volume rate of flow past Section I equals thatpast section III or that past any arbitrary intermediate Section II. Anequivalent statement is that the areas under the velocity-profile curvesshown as I, II and III are all equal.

Since the channel converges in the direction of flow, the shape of thevelocity profile changes from section-tosection, as suggestedschematically in FIG. 2, the profile at exit Section 111 being moreconvex than that at Sections I or II. 5

The exact shape at any given section depends not only on the convergenceof the channel but also on the peripheral velocity of the cylinder andon the difference in elevation between entrance and exit. The higher theentrance above the exit the greater the tendency of the profile to beconvex.

The effect of this mean flow is to turn any fiber that is momentarilytransverse to the general flow direction and to bring it parallel tothis direction. This action is primarily the result of the large radialgradient of velocity. A further straightening effect is produced by theperipheral gradient of velocity, caused by the convergence of thechannel.

In the following discussion the order of magnitude of the forces exertedby the liquid on a fiber in several configurations, is compared with theorder of magnitude of the forces exerted in a standard flat-top card, inwhich the operating fluid is air.

Illa. Forces exerted by the operating fluid on a fiber stationary andtransverse to the flow Half of cylinder velocity, V/2 cm./sec 150.

Length of fiber, L cm 4.

Diameter of fiber, d cm (3/2) X l0 Density of water, p -g./crn. 1. 4OKinematic viscosity of water, v cm. /sec 1 x 10- Considering the fiberas a cylinder transverse to a flowing fluid, it may be found, bywell-known methods as described in the reference, column 4, that theforce on the fiber is on the order of 100 dynes. This estimate is basedon the following Reynolds number at 150 (3/2) X10 W/zl F 1 X 10- :22

From FIGURE 10 of reference, the drag coetficient C 2. From Eq. (10.3)of reference:

For a typical fiat-top card operating on the same size of fiber:

Half of cylinder velocity, V/ 2 cm./sec 540.

Length of fiber, L cm./sec 4. Diameter of fiber, d cm (3/2) X10? Densityof air, p g./ cn1. 1.2 10- Kinematic viscosity v of air cm. /sec 1/7.

The same method yields:

The ratio of the force in the subject apparatus to that in the fiat-topcard is thus about thirty to one.

11b. F iber stationary and parallel to the flow This configurationapproximates that occurring as a fiber is being introduced into thechannel 17 from the slowly rotating, toothed drum or feed roll 14located just upstream from Section I. The liquid flows past the fiber,which can be thought of as a straight cylinder held fast at its upstreamend and parallel to a flow of velocity V/2, where V is the linearvelocity of the surface of the rotating drum or cylinder 24 See FIGURE2. The mean velocity at Section 11 is somewhat less than V/2, but V/Z,is a sufficiently close approximation, since merely the order ofmagnitude of the force is involved. In accordance with well-establishedrules of liquid behavior, the liquid immediately in contact with thestationary fiber is at rest. The velocity of the liquid increasesrapidly with distance from the fiber surface, reaching essentially thatof the free stream a short distance from the surface. This layer offluid surrounding the fiber, in which the velocity rises from Zeroessentially to V/2 is called a boundary layer. Velocity profiles acrossthe boundary layer at three points along the length of the fiber F areshown schematically in FIG. 3. It is seen that the boundarylayerthickness increases gradually with X, that is, the distance from thefront end B of the fiber, reaching a maximum at the downstream end,which is taken at X =L. The shearing movement of the liquid in theboundary layer produces a shear stress at every point of the fibersurface, due to the viscosity of the liquid. This stress is indicated bythe arrows marked T in FIG. 3. It will be seen that T progressivelydecreases as the steepness of the velocity profile decreases, withincrease in X. The resultant efiect of all these parallel shear stressesis a force D tending to move the fiber downstream. As an approximation,D may be computed by methods readily available and designed forapplication to a flat plate, rather than a cylinder.

The order of magnitude of the result thus obtained will be correct.

From Eq. (10.10) of the reference:

X 2.25 10 1r (3/ X 10=* t ne dyne For a fiat-top card:

X X 10 4':,3.6 10- dyne Again the ratio of the forces is about thirty toone.

1111). Fiber moving with the mean velocity of the fluid at its midpointand oriented parallel to the flow On account of the convergence of thechannel, an observer riding on the midpoint of the fiber F (FIG. 3)would see water flowing away from him toward each end of the fiber. Thisrelative motion sets up a boundarylayer flow from the midpoint towardeach end, similar to that described above in paragraph lib. Calculationshows that opposing drag forces due to these boundary layers willproduce a tension in the fiber on the order of 1 l0 dyne. Such a tensileforce would have no effect on a straight fiber parallel to the flow, butif the fiber were initially somewhat skewed it would be pulled intoline. If furthermore, the fiber were initially bowed into, say, asemicircle, the straightening action of the flow would approximatelydouble the radius of curvature of the fiber.

The above discussion shows that the liquid acts in two distinct ways inperforming the carding operation, first, by means of the velocitygradient between the rotating cylindrical surface and the opposedstationary surface; and, secondly, by means of the increase of velocityre- Force=D= 2 sultant from the convergence of the opposite Walls of thechannel. The increasing average velocity of the fluid, caused by thedecrease in width of the channel, tends to pull fibers from a mass andstraighten them. A straightened fiber will travel at the averagevelocity of the fluid at the center of length of the fiber. The rear endof the fiber will be held back by the slower moving fluid, while theforward end of the fiber will be pulled forwardly by the faster-movingfluid. The straightening force on a fiber will be approximatelyproportional to the /2 power of the fiber length and to the 3 /2 powerof the difference between the fluid velocities at the ends of the fiber.Since this velocity difference is essentially proportional to the fiberlength, in the converging flow of the apparatus herein described, thestraightening force will vary approximately as the square of the fiberlength. Furthermore, fibers initially in contact will tend to be pulledapart as they are straightened, and tangled fibers will tend to bepulled out wherever they protrude from amass.

While for convenience in discussion, the wall 18 of the convergentchannel has been considered to have. zero velocity in the direction offluid flow, it will be understood that the invention contemplates theemployment of apparatus wherein both of said walls actually move, but atdifferent velocities in a constant predetermined ratio.

It is obvious that by changing the length of the channel 17, or thespeed of the cylinder 20, the rate of carding may be varied.

While one desirable embodiment has thus been diagrammaticallyillustrated by way of example, and with an explanation of the principlesof operation, it is to be understood that the invention is broadlyinclusive of any and all modifications, both of method and apparatus,falling within the scope of the appended claims.

We claim:

1. That method of carding fibrous material thereby to separate andstraighten individual fibers and to dispose them in predominantlyparallel relation which comprises as steps: suspending the fibrousmaterial in a body of liquid, delivering the liquid with the suspendedfibrous material therein into the wide entrance end of a convergingchannel, defined by opposed spaced walls, one of said walls being fixedand the other wall moving in the direction of the flow of liquid in thechannel, thereby separating and straightening the individual fibers andplacing them in predominantly parallel relation, and discharging fromthe narrower delivery end of the channel substantially the same quantityof liquid per unit of time as is received at the entrance end of thechannel together with the now predominantly parallel fibers, andthereafter separating the fibers from the liquid.

2. That method of treating fibrous material thereby to separate andstraighten individual fibers while disposing them in predominantlyparallel relation, said method comprising as steps: suspending thefibrous material in a liquid of low viscosity, delivering thefiberbearing liquid into the receiving end of a channel to form aflowing stream having opposite, spaced boundaries, one of which isconvex and cylindrically curved and the other of which is concavelycurved, and wherein at the convex boundary the velocity of the liquid issubstantial while at the concave boundary the velocity of the liquid isapproximately zero, and, While maintaining a constant voltune rate offlow throughout the length of the channel, gradually decreasing thedistance between said opposite boundaries thereby progressivelyincreasing the average linear velocity of the stream and so separatingand straightening the fibers and disposing them in predominantlyparallel relation, discharging liquid, wherein the fibers are separated,substantially straight and predominantly parallel, from the channel atthe point at which the boundaries of the stream are at the minimumdistance apart, in quantity per unit of time substantially equal to thatdelivered into the channel, and separat- 8 ing the now substantiallystraight and separate fibers from the liquid so discharged.

3. That method of treating fibrous material thereby to separate andstraighten individual fibers and to dispose the fibers in predominantlyparallel relation, said method comprising as steps: suspending thefibrous material in a body of Water containing a deflocculating agent,agitating the water thereby to bring the fibrous material into intimatecontact with the defiocculating agent, disintegrating masses of coherentfibers, causing the fiber-bearing liquid to flow as a continuous streamhaving spaced opposite boundaries, at one of which the velocity of theliquid is approximately zero while at the opposite boundary the velocityof the liquid is substantial, maintaining constant the volume rate offlow throughout the length of the stream while gradually decreasing thedistance between said boundaries thereby propressively increasing theaverage linear velocity of the stream with resultant straightening andseparating of the individual fibers and disposal of them inpredominantly parallel relation, and at the point of minimum separationof said boundaries, at which the flowing liquid carries fibers whichhave been separated, straightened and disposed in predominantly parallelrelation, discharging the fiber-carrying liquid in quantity, per unit oftime, equal to that at the streams source, and thereafter separating thefibrous material from the liquid.

4. That method of treating fibrous material thereby to separate thefibers, to straighten individual fibers, and to dispose the fibers inpredominantly parallel relation, said method comprising as steps:suspending the fibrous material in a body of liquid of a viscosity ofapproximately that of water, causing the fiber-bearing liquid to flow ina stream having spaced boundary surfaces which so converge that thetransverse thickness of the stream at its delivery end, where thesuspended fibers are substantially parallel, is approximately itstransverse thickness at the entrance end, and wherein one of saidboundary surfaces moves in the direction of fluid flow at a linearvelocity which exceeds that of the opposite boundary surface byapproximately 560 feet per minute, while the volume rate of flow issubstantially constant for all transverse sections of the stream,thereby separating and straightening the fiber, and then removing theseparated and straightened fiber from the liquid.

5. The method according to claim 1, wherein the liquid which contactsthe movable wall is constrained to follow a path which is cylindricallycurved while the liquid which contacts the fixed Wall is constrained tofollow a path which is arcuate and concave and which is eccentricrelatively to said cylindrically curved path, the eccentricity of saidconcave path being such that the channel pro gressively decreases inwidth from a wider end where the liquid enters to a narrower end fromwhich the liquid, containing substantially all of the fibers per unit ofvolume which it had initially and which are now separated, substantiallystraight and predominantly parallel, is discharged.

6. That method of carding textile fibers by the action of hydraulicforces thereby to separate and straighten the individual fibers whichcomprises as steps: suspending the fibrous material in a liquid of lowviscosity, causing said liquid to flow as a stream between an initialpoint and a terminal point while so guiding the liquid that the streamhas one boundary which is convex and cylindrically curved and anopposite boundary, spaced from the first boundary, which is concavelycurved, the curvature of the concavely curved boundary and itsdisposition relatively to the cylindrically curved boundary being suchthat the stream progressively decreases in transverse width from theinitial point to the terminal point, causing the cylindrically curvedboundary of the stream to move at a linear velocity so much greater thanthat of the concave boundary that fibers suspended in the flowing liquidare separated and straightened by hydraulic action, and preventingescape of any liquid constituent of the stream between the initial andterminal points whereby all of the liquid and fibrous material whichenters the stream at the initial point reaches the terminal point, atwhich latter point the suspended fibers are separate and substantiallystraight, and so treating the liquid after leaving the terminal point asto separate the fibrous material from the liquid.

7. Apparatus for so treating fibrous material as to separate andstraighten the fibers and to dispose them in predominantly parallelrelation, said apparatus comprising means defining opposite, spaced,imperforate, smooth walls of a channel for fluid flow, said channelgradually converging from an entrance end to a discharge end, one ofsaid walls being stationary and the other Wall moving at a uniformlinear velocity in the direction of fluid flow in the channel therebycausing fibers, suspended in the liquid flowing along said channel, toseparate from one another, to be straightened, and to be disposed inpredominantly parallel relation, means for delivering fiberbean'ngliquid into the wider, receiving end of the channel at a rate such as tofill the space between said walls, restraining means operative toprevent free entrance of masses of coherent fiber into the channel, andmeans operative to separate fibers from the liquid discharged from thenarrower discharge end of the channel.

8. Apparatus for use in so treating fibrous material as to separate andstraighten individual fibers, said apparatus comprising a rotary,imperforate, smooth-surfaced cylinder, a portion of whose outerperipheral surface constitutes one wall of a channel for the flow offluid, fixed means so defining an opposite wall for the channel that thechannel converges in width from a receiving end to a discharge end, theopposite wall of the channel being imperforate whereby all of the liquidwhich enters the receiving end of the channel is delivered from thedischarge end of the channel, means for so delivering fiber-bearingliquid into the receiving end of the channel as to form a stream fillinthe channel, the peripheral surface of the rotating cylinder movingrelative to the opposite wall in the direction of fluid flow at a muchgreater velocity so that fibers suspended in liquid flowing in thechannel are separated, straightened and disposed in predominantlyparallel relation by hydraulic forces, and means operative to separatethe straightened and predominantly parallel fibers from the liquid.

9. Apparatus according to claim 8, having means for turning the rotarycylinder in a direction such that that portion of its smooth,imperforate peripheral surface which constitutes one wall of the channelmoves in the direction of fluid flow in the channel while the meanswhich defines the opposite wall of the channel is stationary.

19. Apparatus according to claim 8, wherein the means which defines thefixed wall of the channel, which is opposed to the rotating cylinder, isof a concave, arcuate curvature, whose center of curvature is eccentricwith reference to the axis of rotation of the cylinder, its eccentricitybeing such that the wall of the channel progressively decreases from itsreceiving end to its discharge end.

11. Apparatus for use in carding textile fiber thereby to separate andstraighten individual fibers, said apparatus comprising spaced parts sodefining opposite, imperforate walls of a channel that the channelconverges from a receiving end to a discharge end, means for sodelivering fluid-bearing liquid into the receiving end of the channel asto form a stream which fills the channel, means adjacent to saidreceiving end of the channel for restraining masses of coherent fibersfrom freely entering the channel, means for moving at least one of saidwall-forming parts in the direction of fluid flow in the channel at apredetermined linear velocity bearing such a constant ratio to that ofthe other wall-forming part that the fibers suspended in the liquid, inmoving along the channel from its receiving end to its discharge end,are separated and straightened by the operation of hydraulic forces, thequantity of liquid delivered from the discharge end of the channel perunit of time equalling that which enters the receiving end of thechannel per unit of time and carrying with it the separated andstraightened fibers, and means for separating the fibrous material fromthe liquid delivered from the discharge end of the channel.

References Cited by the Examiner UNITED STATES PATENTS 1,708,724 4/ 1929Haug 162216 FOREIGN PATENTS 59,541 6/1938 Norway.

DONALD W. PARKER, Primary Examiner.

1. THAT METHOD OF CARDING FIBROUS MATERIAL THEREBY TO SEPARATE AND STRAIGHTEN INDIVIDUAL FIBERS AND TO DISPOSE THEM IN PREDOMINANTLY PARALLEL RELATION WHICH COMPRISES AS STEPS; SUSPENDING THE FIBROUS MATERIAL IN A BODY OF LIQUID, DELIVERING THE LIQUID WITH THE SUSPENDED FIBROUS MATERIAL THEREIN INTO THE WIDE ENTRANCE END OF A CONVERGING CHANNEL, DEFINED BY OPPOSED SPACED WALLS, ONE OF SAID WALLS BEING FIXED AND THE OTHER WALL MOVING IN THE DIRECTION OF THE FLOW OF LIQUID IN THE CHANNEL, THEREBY SEPARATING AND STRAIGHTENING THE INDIVIDUAL FIBERS AND PLACING THEM IN PREDOMINANTLY PARALLEL RELATION, AND DISCHARGING FROM THE NARROW DELIVERY END OF THE CHANNEL SUBSTANTIALLY THE SAME QUANTITY OF LIQUID PER UNIT OF TIME AS IS RECEIVED AT THE ENTRANCE END OF THE CHANNEL TOGETHER WITH THE NOW PREDOMINANTLY PARALLEL FIBERS, AND THEREAFTER SEPARATING THE FIBERS FROM THE LIQUID. 